High mobility (cement slurry) grouting, or cement or rock grouting, is usually done in fissured rock to reduce water flow along the joints and discontinuities in the rock. Occasionally, cement grouts are injected into the void space within coarse granular soils.
Process
High mobility grouting fills pores in granular soil or voids in rock/soil with flowable particulate grouts. The grout particle and void sizes must be appropriately matched to allow the cement grout to permeate. Depending on the conditions, Portland cement or microfine cement grout is injected under pressure at strategic locations through a single port or multiple port pipes. The grouted mass has increased strength, stiffness, and reduced permeability.
Cement grouting can offer an economic advantage for underpinning applications over alternative approaches such as removal and replacement or piling. It can be performed where access is complex and space is limited. Since the effectiveness of cement grouting is independent of structural connections, this technique is readily adaptable to existing foundations and can typically be accomplished without disrupting normal facility operations.
Specialist contacts
Lucian Spiteri, PE, is a Vice President Pre-Construction at Keller North America.
Lucian has more than 20 years of experience in geotechnical engineering and construction. He holds a Bachelor of Science in Civil Engineering from Manhattan College and has developed deep expertise in ground modification and construction dewatering, including various grouting techniques and systems using wells, wellpoints, and ejectors.
Lucian has contributed to major infrastructure projects such as the Second Avenue, East Side Access, and Number 7 Line Extension in New York City, as well as complex remediation efforts, including a large-scale sinkhole stabilization in Florida and rehabilitation work at the World Trade Center site.
Maxwell Pucciarello, PE, is an Engineering Manager at Keller North America.
Max's role includes oversight and management of Keller's design, estimating, procurement, and QA/QC for specialty grouting jobs, with scopes of work including jet grouting, compaction grouting, rock grouting, and permeation grouting (e.g., cement and chemical). This includes the most complex geotechnical projects, with a wide array of applications, such as temporary and permanent underpinning, bathtub excavations, tunneling, liquefaction mitigation, foundations, support of excavation, and hydraulic barriers.
Max earned a Bachelor of Science degree in Civil Engineering from Rutgers School of Engineering and is a licensed Professional Engineer.
Common uses
- Create barriers to groundwater flow
- Underpin foundations
- Provide excavation support
- Stabilize and strengthen granular soils
Advantages
- Can be effective in reducing ground water flows
- Reduce pumping costs during basement excavation
- Reduced lowering of groundwater levels outside an excavation
- Can reduce rock deformation
Quality assurance
Keller has developed proprietary equipment and software (iGroutTM) to allow real-time monitoring of all parameters during the cement grouting process. The operator can adjust the parameters (such as mix type, flow rate, pressure, and volume limits) based on the real-time acquisition of drilling and grouting data while simultaneously monitoring for any movements or deflections of the ground or nearby structures. Data collected during drilling and grouting is recorded on a server that produces grouting reports and CAD drawings depicting a visual representation of the completed work. This advanced monitoring and control system increases the accuracy, efficiency, and quality control of cement grouting.
Related projects
Infrastructure
Chaplin Station
When unexpected movement and ground disturbance occurred following drilled shaft installation, Keller performed preventative grouting to keep the project on track.
Infrastructure
Muskrat Falls Generating Station
When completed and fully operational, Muskrat Falls will be the second-largest hydroelectric facility in Newfoundland and Labrador.
Infrastructure
Wolf Creek Dam
Wolf Creek Dam, completed in the late 1950s, is comprised of a 1,796-ft-long concrete gravity section and a 3,940-ft-long earthen embankment section, founded on karstic limestone.
Power
NWMO Deep Grouting Trial – Phase 1
Keller drilled and grouted for Phase 1 of a deep grouting trial being executed to determine parameters for the pre-treatment of the underlying rock formation.
Power
NWMO Deep Grouting Trial – Phase 2
Keller implemented lessons learned from Phase 1 into Phase 2 to improve productivity and mitigate risks in the deep grouting trial for the NWMO.
